1. Field of the Invention
The present invention relates to an electroconductive sheet and a touch panel, and relates to, for instance, an electroconductive sheet which is used in a projected capacitive touch panel and the touch panel.
2. Description of the Related Art
A transparent electroconductive film which uses a metal thin wire has been continuously studied as described in U.S. Patent Application Publication No. 2004/0229028 and International Publication No. WO 2006/001461, for instance.
Recently, a touch panel has received attention. The touch panel is mainly applied to devices having a small size such as a PDA (personal digital assistant) and a cellular phone, but is considered to be progressively applied to devices having a larger size such as a display for a personal computer.
In such a trend of the future, a conventional electrode employs ITO (indium tin oxide). The ITO has problems in that the resistance is large, a transmission speed of an electric current between electrodes becomes slow, and a response speed (period of time between the time when finger has touched and the time when position is detected) becomes slow, as the application size increases.
Then, it is considered to lower the surface resistance by an electrode constructed of the metal thin wire. As for a touch panel in which the metal thin wire is used for the electrode, Japanese Patent Application Laid-Open No. H5-224818, U.S. Pat. No. 5,113,041, International Publication No. WO 1995/27334, U.S. Patent Application Publication No. 2004/0239650, U.S. Pat. No. 7,202,859, International Publication No. WO 1997/18508 and Japanese Patent Application Laid-Open No. 2003-099185 are known, for instance.